Verbal Citations add credibility to your speeches and properly give credit to others for their work and ideas. Mentioning ideas and facts that are not your own within your speech, without verbally citing them, is plagiarism.
Verbal Citations shouldn't interrupt the flow of your speech. Use an introductory phrase and keep them brief but include the important "who, what, when" details:
"According to Academy of Motion Picture Arts and Sciences president, Jim Bailey, ..."
"In 2014, Maureen Russell, an ethnomusicologist at UCLA, wrote ..."